The present invention relates to an electrophotographic photoreceptor and a production method of the same, as well as a process cartridge and an image forming apparatus in which said photoreceptor is installed.
In recent years, as electrophotographic photoreceptors, those which comprise organic photoconductive materials have been widely employed. The organic photoreceptors exhibit more advantageous features than other photoreceptors in such a manner that the materials corresponding to various exposure light sources ranging from visible light to infrared light tend to be developed, materials which do not result in environmental pollution can be chosen, and the production cost is relatively low. The only disadvantage is that the mechanical strength is not sufficiently high, and during copying or printing of a number of sheets, the surface of the photoreceptor results in wear and abrasion.
The surface of electrophotographic photoreceptors is subjected to direct application of electrical and mechanical external forces from a charging unit, a development unit, a transfer means, a cleaning unit, and the like. Therefore, durability is required to counter these external forces. Specifically, sufficient durability is required to counter the generation of wear and abrasion due to sliding friction on the photoreceptor surface, and degradation of the photoreceptor surface due to ozone and active oxygen generated during corona discharge.
In order to satisfy the various properties mentioned above which are required for the photoreceptor surface, various factors have been investigated. Namely, it is reported that by employing BPZ polycarbonate as a binder (a binding resin) on the photoreceptor surface, surface wear properties as well as toner filming properties are enhanced. Furthermore, Japanese Patent Publication Open to Public Inspection No. 6-118681 discloses a hardenable silicone resin containing colloidal silica, which is employed as a photoreceptor surface protecting layer.
However, the photoreceptor in which the BPZ polycarbonate binder is employed exhibits insufficient wear resistant properties and exhibits insufficient durability. On the other hand, the surface layer comprised of the hardenable silicone resin containing colloidal silica exhibits improved wear resistant properties, however, during repeated use, electrophotographic properties are insufficient and tend to result in background staining, as well as image blurring and sufficient durability is not achieved.
As a method to solve such problems, Japanese Patent Publication Open to Public Inspection Nos. 9-124943 and 9-190004 propose photoreceptors, having as a surface layer, the layer of a resin prepared by bonding an organic silicone-modified positive hole transportable compound to hardenable organic silicone based high polymer molecules. However, this resin layer results in background staining as well as image blurring at high humidity, and also exhibits insufficient durability.
An object of the present invention is to develop an electrophotographic photoreceptor which exhibits high surface hardness, excellent wear resistance, and stable electrophotographic properties during repeated use at high temperature and humidity, accordingly results in excellent images during repeated use so that the above-mentioned problems can be solved, and a production method of the same, and to further provide a process cartridge and an image forming apparatus employing said photoreceptor.
The inventors of the present invention have exerted their best effort. As a result, it was found that the object of the present invention had been accomplished by employing any of the embodiments described below.
1. An electrophotographic photoreceptor comprising a support, photosensitive layer and a resin layer, said resin layer being obtained by hardening at least one of an organic silicon compound having a hydroxyl group or a hydrolizable group and condensation compound thereof, and a compound represented by formula(1),
A(Q)kxe2x80x83xe2x80x83(1)
wherein A represents a group containing an aromatic group or a heterocyclic group, Q represents a group containing at least one of a hydroxyl group, an amino group, and a mercapto group, and k represents an integer not less than 2, and
wherein said organic silicon compound is three-dimensionally cross-linked.
2. The electrophotographic photoreceptor of item 1, said group Q being represented by formula(2),
R1Zxe2x80x83xe2x80x83(2)
wherein R1 represents nonsubstituted/substituted alkylene group having 1-20 carbon atoms, and Z represents hydroxy, amino, or mercapto group.
3. The electrophotographic photoreceptor of item 2, R1 having a group of CR2R3, and Z being hydroxy group,
wherein each of R2 and R3 is a hydrogen atom, nonsubstituted/substituted alkylene or aryl group having 1-6 carbon atoms.
4. The electrophotographic photoreceptor of item 1, wherein k is an integer of 2 to 10.
5. The electrophotographic photoreceptor of item 1, wherein said resin layer further comprising colloidal silica.
6. The electrophotographic photoreceptor of item 1, wherein said resin layer is a surface layer of the electrophotographic photoreceptor.
7. The electrophotographic photoreceptor of item 1, wherein said resin layer further comprising an anti-oxidant.
8. An electrophotographic photoreceptor comprising
a support,
photosensitive layer and
a resin layer,
said resin layer being obtained by hardening at least one of an organic silicon compound having a hydroxyl group or a hydrolizable group and condensation compound thereof, and a compound represented by formula(3),
B(Q)kxe2x80x83xe2x80x83(3)
wherein B represents a group containing a charge transporting component therein, Q represents a group containing at least one of a hydroxyl group, an amino group, and a mercapto group, and k represents an integer not less than 2, and
wherein said organic silicon compound is three-dimensional cross-linked.
9. The electrophotographic photoreceptor of item 8, said group Q being represented by formula(2),
R1Zxe2x80x83xe2x80x83(2)
wherein R1 represents nonsubstituted/substituted alkylene group having 1-20 carbon atoms, and Z represents hydroxy, amino, or mercapto group.
10. The electrophotographic photoreceptor of item 9, R1 having a group of CR2R3, and Z being hydroxy group,
wherein each of R2 and R3 is a hydrogen atom, nonsubstituted/substituted alkylene or aryl group having 1-6 carbon atoms.
11. The electrophotographic photoreceptor of item 8, said group B being Ar1Ar2Nar3,
wherein Ar1, Ar2 and Ar3 represents aliphatic group or aromatic group.
12. The electrophotographic photoreceptor of item 11, wherein Ar1, Ar2 and Ar3 represents aromatic group.
13. The electrophotographic photoreceptor of item 8, wherein k is an integer of 2 to 10.
14. The electrophotographic photoreceptor of item 8, wherein said resin layer further comprising colloidal silica.
15. The electrophotographic photoreceptor of item 8, said group Q being represented by formula (2),
R1Zxe2x80x83xe2x80x83(2)
wherein R1 represents nonsubstituted/substituted alkylene group or nonsubstituted/substituted allylene group, and Z represents hydroxy, or SiRxe2x80x2pBxe2x80x23-p,
wherein p represents 1 or 2, Rxe2x80x2 represents nonsubstituted/substituted alkyl group or nonsubstituted/substituted allyl group, and Bxe2x80x2 represents hydrolizable group.
16. The electrophotographic photoreceptor of item 15, said organic silicon compound represented by formula(4),
xe2x80x83Rxe2x80x3xe2x80x3Si(OH)4-nxe2x80x83xe2x80x83(4)
wherein Rxe2x80x3xe2x80x3 represents nonsubstituted/substituted alkyl group having 1-20 carbon atoms, nonsubstituted/substituted aryl group, nonsubstituted/substituted fenyl group, nonsubstituted/substituted fuloroalkyl group, xcex3-glycidoxypropyl group, xcex3-methacryloxypropyl group, or xcex3-aminopropyl group, and
wherein n represents an integer of 0 to 3.
17. The electrophotographic photoreceptor of item 15, Z being hydroxy group.
18. The electrophotographic photoreceptor of item 15, wherein a molecular weight of said compound represented by formula (3) is not more than 500.
19. The electrophotographic photoreceptor of item 18, Wherein a molecular weight of said compound represented by formula (3) is not more than 400.
20. The electrophotographic photoreceptor of item 15, wherein k of at least a part of said compound represented by formula (3) is not less than 3.
21. An electrophotographic photoreceptor comprising a support, photosensitive layer and a resin layer, said resin layer being obtained by hardening at least one of an organic silicon compound having a hydroxyl group or a hydrolizable group and condensation compound thereof, and a compound represented by formula(3),
B(Q)kxe2x80x83xe2x80x83(3)
wherein B represents a group containing a charge transporting component therein, Q represents a group containing at least one of a hydroxyl group, an amino group, and a mercapto group, and k represents an integer not less than 2, and
wherein a molecular weight of said compound represented by formula (1) is not more than 500.
22. The electrophotographic photoreceptor of item 21, wherein a molecular weight of said compound represented by formula (3) is not more than 400.
23. The electrophotographic photoreceptor of item 21, said group Q being represented by formula (2),
R1Zxe2x80x83xe2x80x83(2)
wherein R1 represents nonsubstituted/substituted alkylene group having 1-20 carbon atoms, and Z represents hydroxy, amino, or mercapto group.
24. The electrophotographic photoreceptor of item 21, wherein k is an integer of 2 to 10.
25. The electrophotographic photoreceptor of item 21, wherein said resin layer further comprising colloidal silica.
26. The electrophotographic photoreceptor of item 21, wherein said resin layer is a surface layer of the electrophotographic photoreceptor.
27. The electrophotographic photoreceptor of item 21, said group Q being represented by formula (2),
R1Zxe2x80x83xe2x80x83(2)
wherein R1 represents nonsubstituted/substituted alkylene, group or nonsubstituted/substituted allylene group, and Z represents hydroxy, or SiRxe2x80x2pBxe2x80x23-p,
wherein p represents 1 or 2, Rxe2x80x2 represents nonsubstituted/substituted alkyl group or nonsubstituted/substituted allyl group, and Bxe2x80x2 represents hydrolizable group.
28. The electrophotographic photoreceptor of item 27, said organic silicon compound represented by formula (4),
Rxe2x80x3xe2x80x3Si(OH)4-nxe2x80x83xe2x80x83(4)
wherein Rxe2x80x3xe2x80x3 represents nonsubstituted/substituted alkyl group having 1-20 carbon atoms, nonsubstituted/substituted aryl group, nonsubstituted/substituted fenyl group, nonsubstituted/substituted fuloroalkyl group, xcex3-glycidoxypropyl group, xcex3-methacryloxypropyl group, or xcex3-aminopropyl group, and
wherein n represents an integer of 0-3;
29. The electrophotographic photoreceptor of item 28, wherein n of said compound represented by formula(4) is 1.
30. The electrophotographic photoreceptor of item 28, wherein 0.1-5 mol of said compound represented by formula(4) having n=2 is provided for 1 mol of said compound represented by formula(4) having n=1.
31. A production method of an electrophotographic photoreceptor having a support, photosensitive layer and a resin layer, comprising the steps of
(a) coating step applying resin layer comprising at least one of an organic silicone compound having a hydroxyl group or a hydrolizable group and condensation compound thereof, and a compound represented by said formula (1) as defined in item 1,
(b) heating step for hardening the resin layer by cross-linking substantially in a form of triple dimension.
32. The production method of the electrophotographic photoreceptor of item 31, wherein colloidal silica is applied in the resin layer of step (a).
33. The production method of the electrophotographic photoreceptor of item 31, wherein an anti-oxidant is applied in the resin layer of step (a).
34. A production method of an electrophotographic photoreceptor having a support, photosensitive layer and a resin layer, comprising the steps of
(a) coating step applying resin layer comprising at least one of an organic silicone compound having a hydroxyl group or a hydrolizable group and condensation compound thereof, and a compound represented by said formula (3) as defined in item 8,
(b) heating step for hardening the resin layer by cross-linking substantially in a form of triple dimension.
35. The production method of the electrophotographic photoreceptor of item 34, wherein colloidal silica is applied in the resin layer of step (a).
36. The production method of the electrophotographic photoreceptor of item 34, wherein an anti-oxidant is applied in the resin layer of step (a).
37. A production method of an electrophotographic photoreceptor having a support, photosensitive layer and a resin layer, comprising the steps of
(a) coating step applying resin layer comprising at least one of an organic silicone compound having a hydroxyl group or a hydrolizable group and condensation compound thereof,. and a compound represented by said formula (3) as defined in item 8,
(b) heating step for hardening the resin layer by cross-linking substantially in a form of triple dimension.
38. The production method of the electrophotographic photoreceptor of item 37, wherein colloidal silica is applied in the resin layer of step (a).
39. The production method of the electrophotographic photoreceptor of item 37, wherein an anti-oxidant is applied in the resin layer of step (a).
40. An image forming apparatus having a charging unit, an image exposure unit, a development unit, and a transferring means, the image forming apparatus further comprising the electrophotographic photoreceptor of item 1, item 8, or item 21.
41. A process cartridge employed in an image forming apparatus having a charging unit, an image exposure unit, a development unit, and a transferring means, the process cartridge comprising the electrophotographic photoreceptor of item 1, item 8, or item 21 with at least one of the charging unit, image exposure unit, development unit, and transferring means.